Nut-lock.



J. H. & E W. BULLARD. NUT LOCK.

APPLICATION FILED JUNE 20, 1910.

1,029,846, Patented June 18, 1912.

j 7 x w k! t 2 WITNESSES.- NVENTORS. 4/ M A TTQOR/VEYS.

JAMES H. BULLARD AND EDWIN nut held thereby WNTTEU STATES PATENT @FFJWE.

W. BULLARD, OF SPRINGFIELD, MASSACHUSETTS,

ASSIGNORS T0 ALFRED C. FAIRBANKS, OF SPRINGFIELD, MASSACHUSETTS.

NUT-LOCK.

Specification of Letters Patent.

Patented June 18, 1912.

Application filed June 20, 1910. Serial No. 567,763.

To all whom it may concern:

Be it known that we, JAMES H. BULLARD and EDWIN W. BULLARD, bothcitizens of the United States of America, residing at Springfield, inthe county of Hampden and State of Massachusetts, have jointly inventednew and useful Improvements in Nut-Locks, of which the following is aspecification.

Our invention relates to improvements in devices designed to holdinternally screwthreaded members, such as nuts, and prevent them fromturning in a reverse direction on the bolts upon which they are placed,and consists of an annular member having by preference one o-r more flatsides for the convenient application of a wrench, and provided on theinterior of the opening with oppositelydisposed in\i-'ardly-p1-ojectingspiral or helical ridges or threads wedge shaped in cross-section andconforming more or less closely to the recess between the threads on thebolt with which the device is to be used, each of such first-mentionedthreads being less than a single convolution and both being so arrangedthat corresponding or diametrically opposite points are the samedistance from the flat or plane side of the device. A nut on a boltwhich is subjected to incessant, excessive or violent jar or vibrationfrequently becomes loose, retrogrades, and even works oif altogether, asis well known.

The object of our invention is to provide a device of the characterdescribed that is very simple in construction, can be manufactured atcomparatively small cost, is strong and durable. can be easily andquickly applied, and is adequate to prevent a not secured therewith to abolt from getting loose. Neither the nut secured by this nut-lock northenut-lock itself, after the parts have been properly seated, will besufficiently influenced by vibration to cause either to turn, owing tothe peculiar construction of said nutlock and the nature of itsengagement with the and with the threadsof the bolt. We attain thisobject by the means illustrated iii the accompanying drawings, in which-Figure 1 is a plan of a nut-lock which embodies a practicahform pf ourinvention; Fig. 2, a cross-section through said nut-lock taken on lines22, in Fig. 1; Fig. 3, an eleconsiderable frictional ration showingportions of two plates held together by a bolt and nut, the latter beingsecured by a nut-lock similar to that shown in the two preceding views,but somewhat smaller, (the nut-lock in this view is practically across-section taken on lines -3, in Fig. 1) Fig. 4:, a plan of aslightly modified form of the nut lock; Fig. 5, a cross-section throughsuch modification taken on lines 5-5, of Fig. 4: and Fig. 6, across-section taken on lines 6-6 of Fig. 4.

Similar figures refer to similar parts throughout the several views.

The nut-lock shown in the firstthree views consists of a polygonal bodyI, having a countersink 4 in one face, and provided with projectingsegmental ridges or threads 77 on the inside of the opening 8. Thesesegmental ridges or threads are of suitable form to engage with thethreads of the bolt, and they are spiral; that is, each forms a portionof a helix; but their arrangement is such that if they were continued toa length greater than one-half the circumference of the opening in thenut lock they would not join to form a single helix. By this arrangementthe threads are so placed that corresponding opposite points are thesame distance from the fiat or plane side of the nut lock.

With the threads or ridges arranged as described, when the nut lock isapplied to a bolt it assumes a position not at right-angles to the axisof the bolt, thus causing the lock, when screwed down on top of a nut,to touch or bear upon one side of the nut before touching the oppositeside, as shown in Fig. 3. Further tightening of the nut look now has atendency to cause it to assume a position more nearly at right-angles tothe axis of the bolt, thus setting up a pressure of the threads orridges against the sides of the bolt threads. There is also anadditional looking or gripping effect due to the fact that, when thelock is applied to a bolt, the gap or space between the ends of theridges or threads on the nut-lock straddles the thread on the bolt; thenwhen the nut-lock is screwed down to the proper tension against the nut,the tendency to assume a position at right angles to the axis of thebolt causes the ends of the ridges or bear heavily against the alternatesides of oppositely-disposed inwardly threads in the nut lock to 4 thebolt thread, and so grip the bolt thread so tightly as to prevent theloosening of either the nut lock or the nut over which it is applied.

In the drawings we have shown the device with a recess or countersink onone side only, and we prefer this construction. But we do not limitourselves to this one form for the reason that we have demonstrated a byexperiment that the nut lock may be made with the recess on both sides,or with no recess on either side, and that the nut lock is equallyeffective as a lock in any of these forms. Byvplacing the recess all onone side, we are able to make the body of the nut lock suflicientlyrigid to prevent distortion of the nut lock under the tension necessaryto effectually lock the nut in place, while it is possible to apply thenut lock to a bolt that projects through the nut a much shorter distancethan would be the case if there were a recess on the side of the nutlock next to the nut.

- The device shown in Figs. 4, 5 and 6 differs from theothers only inthe shape of its threads 7, which are chamfered or tapered off at 13 towhat amounts practically to vanishing points on the inside instead ofhaving more or less abrupt ends as in the construction shown in Figs. 1and 2. The second device is applied, and operates in the same way, asthe first, but the threads or ridges of the second form do not engage soextensive an area of the bolt threads as do the threads or ridges of thefirst form.

Having therefore described our invention, what we claim and desire tosecure by Letters Patent, is v 1. A nut lock consisting of a rigid platehaving a bolt-receiving opening through it at right-angles the plate andhaving a plurality of spiral projections arranged in the bolt opening,all

at right-angles to the axis of the bore and each touching such planes attwo points.

2. A nut lock consisting of a rigid plate having a bolt-receivingopening through it, the latter having inwardly projectingoppositely-arranged spirally-formed ridges each being-of less lengththan one-half the circumference of the opening and each touching andlocated between two imaginary parallel planes at right-angles to theaxis of the bore.

having a bolt-receiving opening, the latter being provided with aplurality of internally projecting spiral thread-sections, correspondingpoints of each thread section lying in the same plane, parallel to thegeneral plane of the device, substantially as shown.

4:. A nut locking device comprising a rigid body, having a boltreceivingopening through it, and having rigid spirally formed inwardly projectingthread engaging members separated from each other by a gap betweentheir-ends, said members being so disposed as to cause the face of thedevice adjacent the nut to occupy a position on the bolt other than atright angles to the bolt axis.

JAMES H. BULLARD. EDWIN W. BULLARD.

W'itnesse's:

F. A. CUTTER, ALLEN WEBSTER.

lying between two imaginary parallel planes,

40 to the plane of the face of 3. A nut lock consisting of a rigid plate

